Reply by Sawkerf

Since I’m a light-to-medium duty user, I have all Ryobi One+ 18v cordless tools (two drills, hammer drill, impact driver, circ saw, recip saw, trim router, light). Some are Li-Ion and the rest are NiCad. I got one of their six battery chargers for the shop and never run out of juice. When one dies, I put it on the charger and grab a fresh one.

Whatever brand you choose, the big plus in picking a single brand is that you don’t have to keep multiple chargers around.